This application is submitted in response to RFA-MH-09-140 by an interdisciplinary team from four institutions: the Uniformed Services University of the Health Sciences (USUHS), Harvard Medical School (HMS), the University of Michigan (UM), and Columbia University (CU), The team has unparalleled expertise in research on military mental health (USUHS), general population psychiatric epidemiology (HMS), large-scale epidemiological data collection (UM), and neurobiological-clinical research on suicidal behaviors (CU). We propose a multi-phase epidemiological study that considers diverse psychosocial and neurobiological risk and protective factors for suicidal behaviors and secondary outcomes in order to make evidence-based recommendations for implementation of Army suicide prevention interventions. An enriched version of the Army Suicide Event Report (ASER) system will be developed to define the primary outcomes incorporating information from the DoD Medical Mortality Registry (MMR) and Total Army Injury and Health Outcomes Database (TAIHOD). Our study design will include both a retrospective case-control component for quick efficient hypothesis testing and a prospective survey component to predict subsequent suicidal behaviors and secondary outcomes (onset, persistence, worsening of DSM-IV disorders, suicide ideation, suicide plans). We will also use data from the ongoing Pre- and Post-Deployment Health Reassessment Program (PDHRP) surveys as secondary outcomes. The case-control survey will study soldiers who made nonfatal attempts and relatives of soldiers who committed suicide in a psychological autopsy framework. Parallel data will be collected from carefully matched controls. Blood samples and, in the case of nonfatal attempters and their controls, saliva samples will be collected to allow neurobiological risk and protective factors to be studied. The survey component will include active duty personnel across all phases of Army service. Survey reports will be link to subsequent ASER records and PDHRP reports to study prospective associations of predictors with suicidal behaviors and secondary outcomes. A number of innovative measurement, design and analysis features will be used to increase chances of discovering effective intervention possibilities. RELEVANCE: The problem of Army suicide is one of great importance because an effective military force requires its members to be not only physically healthy but also mentally healthy. The relevance of a current study of Army suicide is heightened by the alarming rise in the suicide rate of US Army personnel over the past five years. The research proposed here has the potential to be of great value in helping the Army select optimally effective interventions to address this problem.